386,000 cases of bladder cancer are diagnosed globally each year, including 70,500 cases per year in the United States. The incidence of bladder cancer is three times higher in men than in women. The highest incidence and prevalence are found in the European Union, North America, North Africa, and the Middle East
Smoking is the greatest risk factor for bladder cancer. Additional risk factors include chemical exposure, chemotherapy (such as Cytoxan), radiation treatment, and chronic bladder infection.
Bladder tumors include papillary tumors, which are urothelial carcinomas that grow narrow, finger-like projections; and nonpapillary (sessile) tumors, such as carcinoma-in-situ, which are less common but have a high risk of becoming invasive.
Symptoms of bladder cancer can include abdominal pain, blood in the urine, bone pain or tenderness, fatigue, painful urination, frequent urination, urinary urgency, incontinence, and weight loss. Diagnosis is generally based on imaging, urinalysis, and/or biopsy.
The prognosis for bladder cancer depends on the stage of cancer at diagnosis. The prognosis for early tumors is favorable, while the prognosis for advanced tumors is poor. Long-term follow up is recommended to detect cancer recurrence, which occurs in up to 70% of bladder cancers. For the first two years, cystoscopy and urine cytology are recommended every 3 to 4 months, and then at longer intervals in subsequent years, often for the patient's lifetime. These methods are invasive and costly, making bladder cancer one of the most expensive cancers to treat from diagnosis until death.
Existing non-invasive diagnostic tests include ImmunoCyt™ (Scimedx, Denville, N.J.) and UroVysion® (Abbott Molecular, Abbott Park, Ill.) ImmunoCyt™ is a cytology assay that uses a cocktail of three monoclonal antibodies labeled with fluorescent markers to detect certain cellular markers of bladder cancer in exfoliated cells isolated from urine samples ImmunoCyt™ is used in conjunction with standard urine cytology to improve cytology's sensitivity at detecting tumor cells. UroVysion® is also a cytology-based assay, which detects aneupoloidy in certain chromosomes via fluorescent in situ hybridization (FISH). Determination of the results is conducted by enumerating signals through microscopic examination of the nucleus of cells in urine.
Improved methods for early detection of bladder cancer are needed. In particular, an accurate urine-based diagnostic test that does not rely on cytology could reduce the need for costly and invasive cystoscopy and labor-intensive and potentially subjective cytology assays.